London, 1899, but not the London you know.
Here, the River Thames hangs upside down in the sky, steam trains race through the clouds, and a vast transparent dome covers the entire city. This device, known as Amber City, seals humanity's last refuge outside of time.
Seventeen-year-old machinist's apprentice Ethan accidentally comes into contact with forbidden knowledge from the “Upside-Down Sea,” and his shadow begins to develop a will of its own. At the same time, cracks appear in the protective barrier at the edge of Amber City, and the “indescribable things” outside begin to stir.
While everyone else believes the cracks are caused by mechanical failure, Ethan alone realizes they are an “invitation” deliberately created by some presence. As his investigation deepens, he is drawn into a conspiracy spanning three centuries: Amber City is not a refuge, but a colossal prison. Humanity is trapped inside not because there are monsters outside, but because the people within the city have already become monsters.
Now the Upside-Down Sea is on the verge of collapsing, and Amber City's time is running out. Before the city plunges into eternal madness, Ethan must choose: repair the barrier and keep the lie alive, or shatter the amber and face the bloody truth?
